textproduct: Quad Cities

KEY MESSAGES

- There is a Marginal (level 1 of 5) risk for severe storms Wednesday night and Thursday.

- Building heat this weekend and into early next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 155 AM CDT Tue Jul 7 2026

Early morning water vapor and radar mosaics show a weakening line of showers and thunderstorms dropping south over MN. Closer to home, surface observations and RAP analysis has the center of a 1019mb high over southwest WI near Boscobel. Temperatures and dewpoints were in the mid to upper 60s, with dewpoint depressions in the 0-2 degree range under clear skies.

Patchy shallow fog will be possible prior to sunrise today, especially in river valleys and low lying areas. Some guidance was even showing some dense fog developing over northeast IA before 12z, but has now backed off on this solution. Otherwise, another seasonable summer day is anticipated with similar humidity levels compared to yesterday. With plentiful sunshine and a high sun angle, afternoon highs should top out a few degrees higher than Monday with readings in the mid to upper 80s.

Tonight, surface high slides southeast with weak return flow developing and slightly warmer temps aloft. This will result in overnight lows only dropping into the upper 60s.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 155 AM CDT Tue Jul 7 2026

Upper level pattern to transition to a more zonal flow, with several shortwaves moving through by the end of the work week. During the day on Wednesday, the active storm track will remain north of the area over MN and WI, as a cool front drops south into IA. While forcing along and behind the front is not overly impressive, scattered showers/storms are still forecast to develop aided by 30-40kt mid-level flow, dropping southeast closer to the northwest portions of the CWA late Wednesday/early Thursday. The question becomes will they actually reach our area before dissipating and CAM guidance is mixed. Better synoptic lift will be displaced to the north and to the west of the CWA, but if storms do reach the northern CWA they will occur in a high PW+sufficient thermodynamic environment to support a few isolated strong to severe storms. RAP forecast soundings also support this idea and still has DCAPE values around 600 J/Kg at 03z near the Hwy 20 corridor. Not all areas will see rain however and there will be many dry hours during the day Thursday.

The aforementioned cool front to drop south and stall out somewhere over the southern half of the CWA Thursday afternoon while another stronger shortwave shown by several deterministic and ensemble solutions moves across Iowa. A more favorable kinematic parameter space is also being suggested with this wave leading to a chance of severe storms. As a result, the SPC now has a Marginal (level 1 of 5) Risk for areas along and south of line from Washington IA to Sterling IL. In addition, a very moist environment will be in place leading to a heavy rain threat.

Beyond Friday, all deterministic and ensemble guidance show a large anomalous 598 dam 500mb ridge building into the central CONUS. Above normal temperatures are likely and with the maturing crops adding additional moisture into the atmosphere, we could see more heat headlines by early next week. The latest CPC Day 6-10 day temperature outlook has 85% combined probabilities of near-above normal temperatures.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1152 PM CDT Mon Jul 6 2026

High pressure overhead and calm wind in a moist BL will allow for at least patchy fog to develop prior to sunrise Tuesday. With NBM MVFR probabilities over 30% decided to add MVFR vsbys at all sites, with longest durations at CID/DBQ. After sunrise, any shallow fog will quickly lift, with VFR conditions expected through the rest of the TAF cycle with light and variable wind turning southerly by the end of the period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.